Severe skeletal bimaxillary protrusion treated with micro-implants and a self-made four-curvature torquing auxiliary: A case report

Table 1 Cephalometric measurements

Measurement	Norm ± SD	Pretreatment (July 2013)	Leveling and aligning (June 2014)	Progress I (Oct, 2015)	Progress II (Sep, 2016)	Posttreatment (Jun, 2017)	Retention (Mar, 2019)
SNA	82.8 ± 4.0	82.5	82.0	81.0	81.0	80.5	80.5
SNB	80.1 ± 3.9	71.0	76.0	72.5	72.5	72.5	72.6
ANB	2.7 ± 2.0	11.5	6.0	8.5	8.5	8.0	7.9
SND	77.3 ± 3.8	70.0	73.0	70.0	71.0	71.0	71.3
U1-NA (mm)	5.1 ± 2.4	5.0	6.8	-0.7	1.8	2.0	1.8
U1-NA	22.8 ± 5.7	25.7	31.1	6.0	8.0	10.0	9.5
L1-NB (mm)	6.7 ± 2.1	10.0	13.6	6.4	7.2	6.5	6.0
L1-NB	30.3 ± 5.8	30.7	42.5	29.0	24.5	24.0	24.5
U1-L1	124.2 ± 8.2	116.0	95.5	136.0	139.0	135.0	137.9
GoGn-SN	32.5 ± 5.2	33.4	33.8	33.1	33.7	33.0	33.3
SE	20.2 ± 2.6	17.9	17.1	20.0	17.0	17.0	16.5
SL	52.1 ± 5.4	44.3	40.1	38.6	36.0	36.0	36.5
FMA	31.3 ± 5.0	31.0	31.6	31.1	30.5	30.3	30.5
FMIA	54.9 ± 6.1	46.0	34.0	45.0	52.0	52.0	53.2
IMPA	93.9 ± 6.2	103.0	114.0	102.0	98.0	98.0	96.5
UL-EP (mm)	1.0 ± 2.0	7.0	6.8	2.4	0.2	-0.7	-0.7
LL-EP (mm)	-1.0 ± 1.0	4.0	2.1	0.5	-0.8	-1.2	-1.3
Pog-Pog′ (mm)	9.9 ± 2.1	14.2	14.6	16.8	16.4	16.7	17.1
Gn-Gn′ (mm)	6.0 ± 2.2	4.5	6.0	6.6	7.3	7.7	8.3
Me-Me′ (mm)	6.5 ± 2.1	6.5	6.3	7.1	6.3	6.6	6.8

ANB: Point A-nasion-point B; EP: E plane; FMA: Frankfort to mandibular plane angle; FMIA: Frankfort mandibular incisor angle; Gn: Mandibular unit length; GoGn: Angle between the SN planes and mandibular plane: IMPA: Angle between the long-axis of the mandibular incisors and mandibular plane; L1: Lower incisor; LL: Lower lips; Me: Facial unit height; NA: Nasion to point A; NB: Nasion to point B; Pog: Pogonion; SE: Cranial suture between the sphenoid bone and ethmoid bone; SL: Sublabialis; SN: Sella-nasion plane; SNB: Sella-nasion-B point; SND: Sella-nasion-D point; U1: Upper incisor; UL: Upper lips.